RU2521826C2 - Method of generating instruction for triggering sniper active protection system, "anti-sniper" radar set - Google Patents

Abstract

FIELD: physics, navigation.

SUBSTANCE: invention relates to high-speed radar engineering and can be used in designing a system for active protection of an object (sniper) from an ultrahigh speed small target. The method includes generating an instruction for triggering the active protection system of the object only when the duration of a second time interval is equal to half of a first time interval, where the first is generated between the onset and detection at a radar system of signals at differential frequency Fp₄=(N+4)Fp and Fp₃=NFp, respectively, where N is a number greater than 3, and the second is generated between the onset and detection of signals at differential frequency Fp₂=3Fp and Fp₁=Fp=Fdo+A=2Vofo/C+Btz, respectively, when the distance between the antenna of the radar station and the target D₄=(Fp₄-A+Fi/3)C/2B, D₃=(Fp₃-A+Fi/3)C/2B, D₂=(Fp₂-A+Fi/3)C/2B, D₁=(Fp₁-A+Fi/3)C/2B, where Fi=2Vifo/C is Doppler frequency, C is the speed of light, Vo is radial velocity of a safety ordnance, fo is the frequency of the emitted chirp signal, B=Fmdfm and A=Btz respectively denote the rate of change of frequency of the chirp signal and part of the frequency of the difference signal resulting from artificial delay by a time tz of the emitted chirp signal, Fm and dfm denote modulation frequency and frequency deviation of the chirp signal, respectively. The "Anti-sniper" radar set comprises an antenna, a delay element, two mixers, a chirp signal transmitter, a differential frequency filter, two continuous frequency generators, an analogue adder, a wide-band filter and a narrow-band filter, an amplitude detector, a limiting amplifier, a comparator, a pulse former, a count pulse generator, a bidirectional counter, a digital comparator, a monostable multivibrator, three AND elements, two OR elements, a halver, a switch, a memory unit and a code converter.

EFFECT: reduced weight, size and cost characteristics of radar for generating instructions for triggering protection systems.

2 cl, 2 dwg

Description

The invention relates to high-speed radar technology and can be used to create an active system for protecting a sniper from hitting it with an ultra-fast small-sized bullet.

A known method of forming a command to launch a protective munition and a device for its implementation (patent RU, 2374597, IPC F41H 11/02, 12/20/2007).

A known method of forming a command to launch a protective munition, initially combined with the radar and the protected object and fired at the required point in time to the intended point in space for a meeting within a known time after a shot with a target approaching the radar, is that the launch command pulse a protective munition is formed only when the moments in time of issuing commands to launch a protective munition, determined on radar spaced in space, coincide in time at the beginning of occurrence and detection on them a signal with a frequency of Fdo = 2Vo fo / C, when the target will be located at a distance from the radar, equal to Do + (Vi / Vo) Do, where fo is the frequency of the emitted continuous signal with frequency modulation according to a one-sided ramp law (VLFM signal),

Vo, Vi, C - respectively, the radial speeds of the protective munition and the target and the speed of light,

Do - the distance from the radar to the estimated point of meeting the target with the ammunition.

The known method is implemented as a device for generating a command to launch a protective munition, made in the form of two spaced apart radars in the space to determine the moment of issuing a command to launch a protective munition, the outputs of which are connected to the inputs of the coincidence unit, each of the radars containing a transmitting and receiving antenna, an input which, working on the transmission, is connected to the high-power output of the continuous LFLM transmitter, and the output, working on reception, is connected to the first input of the mixer, the second input of which is connected to the transmitter output, and the output to the input of the difference frequency filter, as well as a signal detector of the narrow-band frequency spectrum, the output of which is connected to the output bus, and the input to the output of the difference frequency filter and which contains a continuous frequency signal generator, a second mixer, broadband filter, limiter amplifier, narrow-bandpass filter, amplitude detector, comparator and pulse shaper, while the second input of the comparator is connected to the reference voltage bus, and the second th input of the second mixer to the input bus.

A disadvantage of the known device is its significant mass and dimensions, determined by two radars.

The aim of the invention is to reduce the weight and size and cost characteristics of the radar forming commands for the operation of protection systems.

This goal is achieved through the implementation of the Antisniper radar using only one radar.

Figures 1 and 2 respectively show a block diagram of the Antisniper radar and a drawing explaining its operation when a bullet approaches it.

The formation of a command for triggering an active sniper protection system, a system combined with the position of a sniper, consists in determining the moment of issuing a command to the radar set at the beginning of detection of a specific differential frequency signal on the radar, and the command for triggering an active sniper protection system is generated only if the duration is equal of the second and half of the first time intervals, the first of which is formed between the occurrence and detection signals on the radar, respectively, of the difference frequency Fp ₄ = (N + 4) Fp and Fp ₃ = NFp, where N is a number greater than 3, and the second is between the beginnings of occurrence and detection, respectively, of signals with a difference frequency of Fp ₂ = 3Fp and Fp ₁ = Fp = Fdo + A = 2Vofo / C + Btz, where C and Vo are the speed of light and the response of the active protection system, fo is the frequency of the emitted continuous signal with frequency modulation according to a one-sided sawtooth linearly increasing law (NLFM signal), B = Fmdfm is the rate of change of the frequency of the NLFM signal,

A = Btz - part of the frequency of the difference signal arising due to the artificial delay for the time tz of the emitted NLFM signal

Fm and dfm, respectively, the modulation frequency and frequency deviation of the NLFM signal, when the distances between the radar antenna and the target are, respectively: D ₄ = (Fp ₄ - A + Fi / 3) C / 2B, D ₃ = (Fp ₃ -A + F3) C / 2B, D ₂ = (Fp ₂ -A + Fi / 3) C / 2B, D ₁ = (Fp _1- A + Fi / 3) C / 2B, where Fi = 2Vifo / C is the Doppler frequency from the bullet, exactly approaching the radar antenna with a radial speed Vi.

The Antisniper radar contains an antenna 1, the output of which, operating at reception, is connected to the first input of the mixer 4, the second input of which is connected to the low-power output of a continuous signal transmitter 3 with frequency modulation according to a one-sided ramp law (NLFM signal), and the output to the input of the filter 5 difference frequencies, the output of which is connected to the second input of the second mixer 25, as well as a generator 22 of a continuous frequency and a series-connected second mixer 25, a broadband filter 26, amplifier-ogre antichoke 27, narrow-band pass filter 28 (UPF), amplitude detector 29, comparator 30 and pulse shaper 32, while the second input of the comparator is connected to the voltage reference bus 31, while the input of the antenna 1 operating for transmission is connected to a high-power output of the transmitter 3 NLFM signal through delay element 2, as well as newly introduced: second continuous frequency generator 23, analog adder 24, shift register 11, counting pulse generator 12, counter 15, digital comparator 16, multivibrator 17, three elements 13, 1 9, 20 AND, two elements 9, 14 OR, a divider 18 into two, a switch 10, a memory unit 6, a code converter 8, while the outputs of the first and second generators 22 to 23 continuous frequencies are connected respectively to the first and second inputs of the analog adder 24 , the output of which is connected to the first input of the second mixer 25, the fourth output of the shift register 11 is connected to the input of the standby multivibrator 17 and through the first element 9 OR to the reset inputs of the register AND shift, memory unit 6 and the reverse counter 15, and the second input of the first element 9 OR connected to the output switch 10, the first output of the shift register 11 is connected to the enable input of the summation of the reverse counter 15 and the second input of the second element 19 AND, the third output of the shift register is connected to the enable input of the subtraction of the reverse counter 15 and the second input of the third element 13 And, the output of the generator 12 of counting pulses is connected through a divider 18 into two and a second element 19 AND to the input of the second element 14 OR, and also through the third element 13 And to the second input of the second element 14 OR, the output of which is connected to the input of the account of the counter 15, the output of which are connected to the first inputs of the digital comparator 16 and through a series-connected memory unit 6 and the code converter 8 to its second inputs, the installation input of the memory unit 6 is connected to the second output of the shift register 11, the output of the digital comparator 16 is connected to the second input of the first element 20 AND , the first input of which is connected to the output of the waiting multivibrator 17, and the output to the output bus 21, the output of the driver 32 is connected to the input of the shift register 11.

Consider, including by example, the operation of the Antisniper radar.

Let through the antenna 1 of the radar (Fig. 1) a signal generated by the transmitter and delayed by tz = 5 × 10 ^-8 with an NLFM delay element with signal parameters, for example, Fm = 10 ⁶ Hz, dfm = 5 × 10 ⁷ Hz, fo = 100 GHz, selected at Do = 0.3 m, Vo = 150 m / s and Do / Vo = fo / Fm × dfm = 0.002 s, as well as at a bullet speed Vi = 1 km / s and reference signals, for example, fop- ₁ = 2.6 MHz and fop- ₂ = 31.2 MHz, coming, for example, through an analog adder 24 from two continuous frequency generators 22 and 23 to the second mixer 25, and at: 2V = 2Fmdfm = 10 ¹⁴ Hz ² , A = Bt _z = 2.5 × 10 ⁶ Hz, Fi = (2/3) × 10 ⁶ Hz, Fp ₄ = 36.4 × 10 ⁶ Hz, Fp ₃ = 26 × 10 ⁶ Hz, Fp ₂ = 7 , 8 × 10 ⁶ Hz, Fp ₁ = Fp = 2.6 × 10 ⁶ Hz, N = 10, Fdo = 2Vofo / C = 100 Hz.

Then, if the bullet is at a speed of 1 km / s exactly along the OB line (Fig. 2), it will approach the radar antenna 1 located at point O and will be located at a distance from the antenna, respectively: OM = [Fp_four-A + Fi] C / 2B = [36.4 × 10⁶-2.5 × 10⁶+ (2/3) × 10⁶] (3 × 10⁸ m / s) / 10^fourteen= 103.7 m, OD = [Fp₃-A + Fi] C / 2B = [26 × 10⁶-2.5 × 10⁶+ (2/3) × 10⁶] (3 × 10⁸m / s) / 10^fourteen= 72.5 m, OS = [Fp₂-A + Fi] C / 2B = [7.8 × 10⁶-2.5 × 10⁶+ (2/3) × 10⁶] (3 × 10⁸ m / s) / 10^fourteen= 17.9 m, OB = [Fp_four-A + Fi] C / 2B = [2.6 × 10⁶-2.5 × 10⁶+ (2/3) × 10⁶] (3 × 10⁸m / s) / 10^fourteen= 2.3 m

then in the radar, in the first mixer 4, differential signals will be formed, respectively, with frequencies:

Fp ₄ = (N + 4) Fp = 36.4 MHz, Fp ₃ = NFp = 26 MHz, Fp ₂ = 3Fp = 7.8 MHz, Fp ₁ = Fp = 2.6 MHz.

Moreover, when the conditions are met:

A + (2OM × Fmdfm / C) - (2Vi × fo / C) = Fp ₄ , A + (2OM × Fmdfm / C) - (2Vi × fo / C) = Fp ₃

A + (2OC × Fmdfm / C) - (2Vi × fo / C) = Fp ₂ , A + (2OC × Fmdfm / C) - (2Vi × fo / C) = F _Pl

at the radar output (output of the pulse shaper 32), pulse commands will be generated. Moreover, the first two impulse commands will be generated after a time interval (OM-OD) / Vi = 0.0312 s, and the third and fourth exactly 2 times (0.0312 s / 0.0156 s = 2 times) faster, i.e. . through (OC-OB) / Vi = 0.0156 s.

If the bullet approaches 1 km / s with a miss to the radar antenna 1, parallel to the KE line, then at the radar output impulse commands will be generated when the following conditions are satisfied:

-K₄M $${}_1^2$$

/OK₄]/C=Fp₄,A + 2OK ₄ Fmdfm / C-2Vi × fo [Cosβ ₄ = (√OK $${}_{\mathrm{four}}^2$$

-K ₄ M $${}_{\mathrm{one}}^2$$

/ OK ₄ ] / C = Fp ₄ ,

-K₃Д

/OK₃]/C=Fp₃,A + 2OK ₃ Fmdfm / C-2Vi × fo [Cosβ3 = (√OK $${}_3^2$$

-K ₃ D

/ OK ₃ ] / C = Fp ₃ ,

-K₄С $${}_1^2$$

/OK₂]/C=Fp₂,A + 2OK ₂ Fmdfm / C-2Vi × fo [Cosβ ₂ = (√OK $${}_2^2$$

-K _{4 s} $${}_{\mathrm{one}}^2$$

/ OK ₂ ] / C = Fp ₂ ,

-K₁В

/OK₁/C=Fp₁.A + 2OK ₁ Fmdfm / C-2Vi × fo [Cosβ ₁ = (√OK $${}_{\mathrm{one}}^2$$

-K ₁

/ OK ₁ / C = Fp ₁ .

-K₄M

)-(√OK

-К₃Д

)]/Vi=0,0312021 c, а третья и четвертая быстрее, но только в 0,0312021 с/0,016086 с=1,94 раза, а не 2 раза, т.е. через (КК₂-KK₁)/Vi=[(OK₂ ²-K₂C² ₁)-[√OK $${}_1^2$$

-K₁B $${}_1^2$$

/OK₁)]Vi=0,016086 с.It is easy to select these equations and find the distances by selecting the values OK ₄ , OK ₃ , OK ₂ , OK ₁ and, for example, with K ₄ M ₁ = K ₃ D ₁ = K ₂ C ₁ = K ₁ B ₁ = 1 m: OK ₄ = 103.6999 m, OK ₃ = 72.4999 m, OK ₂ = 17.898 m, OK ₁ = 2.045 m, at which pulse commands will also be generated at the radar output. Moreover, the first two impulse commands will be generated after a time interval (KK ₄ -KK ₃ ) / Vi = [(√OK

-K ₄ M

) - (√OK

-K ₃ D

)] / Vi = 0.0312021 s, and the third and fourth are faster, but only 0.0312021 s / 0.016086 s = 1.94 times, and not 2 times, ie via (KK ₂ -KK ₁ ) / Vi = [(OK ₂ ² -K ₂ C ² ₁ ) - [√OK $${}_{\mathrm{one}}^2$$

-K ₁ B $${}_{\mathrm{one}}^2$$

/ OK ₁ )] Vi = 0.016086 s.

That is, when the bullet is exactly closer to the radar antenna 1, the first two pulse commands will always be formed on it after a time interval 2 times longer than the third and fourth pulse commands. When the bullet approaches the radar antenna 1 with a miss, the first two pulse commands will be formed on it after a time interval that is also longer than the third and fourth pulse commands, but not 2 times, but less, for example, 1.94 times . Moreover, the greater the slip, the greater the difference. So, with a missed bullet of not 1 m, but 0.5 m, the intervals will differ by 1.994 times.

It is obvious that the dependence of the duration of the second time interval on the missed missile in the radar antenna 1 can be used to detect whether or not the bullet hit the protected object, as well as the increase, due to the artificial delay of the NLFM signal, the value of the frequency of the difference signal with Fdo = 100 kHz to Fp = 2.6 MHz leads to the fulfillment of the condition Fp> Fm and, accordingly, to a more reliable detection of the difference signal on the radar.

Bullet - a small target with a length of L = 1 cm flies a distance S = 10 cm with a speed of V = 1 km / s for a time t = S / V = 10 ^-4 s. If we assume that only at this time the maximum of the useful signal is formed at the output of UPF 28, then its passband should be approximately equal to Δf = 1 / 3t = 1/3 × 10 ^-4 c = 33.333 kHz.

Over the passage of a distance by a bullet, for example, 17.9 m-2.3 m = 15.6 m, the frequency of the difference signal changes, albeit by 5.2 MHz, at a speed of 5.2 MHz / 15.6 m = 0.333 MHz / m, or after 10 cm at 33.333 kHz.

That is, if a difference signal is passed through UPF 28 with a central frequency of fc = 5.2 MHz and Δf = 33.333 kHz, for example, with a frequency of Fp = 5.2 MHz = 2.6 MHz + 2.6 MHz = 7.8 MHz-2 6 MHz = 31.2 MHz-26 MHz = 36.4 MHz-31.2 MHz, then it will reach its maximum value after a time t ¹ = 3 / Δf = 9 × 10 ^-5 s, sufficient to detect the difference signal , and without highlighting its harmonics.

The filter 5 difference frequencies mainly plays the role of suppressing the total conversion frequencies, input signals and the local oscillator signal.

Before starting the radar from the switch 10, through the element 9 OR, to the shift register 11, the reversible counter 15 and the memory unit 6 give a short pulse, which sets the device data to its original state.

When a bullet spans a point of space M or K "at the output of the radar — the output of the narrowband frequency spectrum detector (second mixer 25, continuous-frequency oscillators 22 and 23, broadband filter 26, limiter amplifier 27, UPF 28, amplitude detector 29, comparator 30, former 32 pulses, analog adder 24) the first pulse command will be generated, which shift register 11 will be transferred to a state with a different potential at its first output and which will be given permission to start the counter 15 counter pulses, f 12 counting pulses, generated by the generator, and arriving at its counting input through a divider 18 into two and elements AND 19 and OR 14.

When a bullet spans a point in space D or K ₃ , a second pulse command will be generated at the radar output, by which the shift register 11 will be transferred to a state with a different potential at its first output and which will be prohibited from counting pulses.

When a bullet spans a point in space C or K ₂ , a third pulse will be generated at the radar output — a command that will shift register 11 to a state with a different potential at its third output and that will be given permission to start the reversible counter 15 subtract counting pulses arriving at its counting entrance through the elements AND 13 and OR 14.

When a bullet spans a point in space B or K ₁ , a fourth pulse command will be generated at the radar output, by which the shift register 11 will be transferred to a state with a different potential at its fourth output. At the same time, a high potential is established at the output of the waiting multivibrator 17, and the reverse counter 15, the memory unit 6, and the shift register 11 are set to the initial state.

If so many (almost as many) counting pulses are written to the reverse counter 15 as written off, which will correspond to the case of a direct hit of a bullet in the antenna 1 and the protected object, then a high potential will be generated at the output of the digital comparator 16, which through the And 20 element will arrive on the output bus 21 as an impulse command, allowing, for example, to undermine the charge of the device, which raises a barrage device (metal plate) in the path of the bullet.

If, however, less (much) counting pulses are written to the reverse counter 15 than written off, which will correspond to the case of a bullet not falling into the radar antenna 1 and the protected object, then low potential will be generated at the output of digital comparator 16, since the digital codes at its inputs will be much more different than in the previous case and the output bus 21 pulse command will not be received.

Obviously, the values of the time intervals of 0.5 MD / V1, CB / Vi, 0.5 M ₁ / Vi and C ₁ B ₁ / Vi at a different speed of approaching the bullet to the radar will be different. In order to exclude the dependence of the radar operation on the speed of the bullet, measure the time interval between potential changes at the first and second outputs of the shift register 11, proportional to the speed of the bullet and stored in the memory unit 30 after applying the corresponding potential from the second output of the shift register 11, and set at the outputs of the code converter 8, a previously known digital number for comparison with the code at the output of the counter 15.

Claims (2)

1. The method of forming a command to fire the active protection system of a sniper, a system combined with the position of a sniper, which consists in determining the moment of issuing a command at a radar station, set at the beginning of detection of a specific differential frequency signal on the radar, characterized in that the command to fire active protection systems of a sniper form only when the duration of the second and half of the first time intervals is equal, the first of which is formed between the beginnings of occurrence and detection a radar respectively difference frequency signal Fp ₄ = (N + 4) Fp and Fp ₃ = NFp, where N - number greater than 3, and the second - between the beginning of the occurrence and detection, respectively, the difference frequency signal Fp ₂ = 3Fp and Fp ₁ = Fp = Fdo + A = 2Vofo / C + Btз, where
C and Vo, respectively, the speed of light and the response of the active protection system,
fo is the frequency of the emitted continuous signal with frequency modulation according to a one-sided sawtooth linearly increasing law (NLFM signal),
B = Fmdfm - the rate of change of the frequency of the NLFM signal,
A = Btz - part of the frequency of the difference signal arising due to the artificial delay for the time tz of the emitted NLFM signal,
Fm and dfm are the modulation frequency and frequency deviation of the NLFM signal, respectively. 2. A device for generating a command for triggering an active sniper protection system, comprising an antenna, the output of which, being received, is connected to the first input of the mixer, the second input of which is connected to the low-power output of a continuous signal transmitter with frequency modulation according to a one-sided ramp law (NLFM signal) ), and the output to the input of the filter of differential frequencies, the output of which is connected to the second input of the second mixer, as well as a continuous frequency generator and series-connected second a mixer, a broadband filter, an amplifier-limiter, a narrow-band bandpass filter, an amplitude detector, a comparator and a pulse shaper, while the second input of the comparator is connected to the reference voltage bus, characterized in that the input of its antenna working on the transmission is connected to the high-power output of the NLCM transmitter the signal through the delay element, as well as the following are introduced into it: a second continuous frequency generator, an analog adder, a shift register, a counting pulse generator, a reversible counter, a digital comparator, waiting multivibrator, three AND elements, two OR elements, a divider by two, a memory block, a code converter, a switch from which a short pulse is supplied, which sets the device to its initial state, while the outputs of the first and second continuous frequency generators are connected respectively to the first and second the inputs of the analog adder, the output of which is connected to the first input of the second mixer, the fourth output of the shift register is connected to the input of the standby multivibrator and through the first OR element to the reset inputs of the shift register, block memory and a reversible counter, and the second input of the first OR element is connected to the output of the switch, the first output of the shift register is connected to the enable input of summation of the reverse counter and the second input of the second element And, the third output of the shift register is connected to the input of subtracting the reverse counter and the second input of the third element And, the output of the counter pulse generator is connected through a divider to two and the second AND element to the input of the second OR element, and also through the third AND element to the second input of the second OR element, the output of which is connected to the count input of a reversible counter, the outputs of which are connected to the first inputs of the digital comparator and through the memory block and the code converter connected in series to its second inputs, the installation input of the memory block is connected to the second output of the shift register, the output of the digital comparator is connected to the second input of the first element And, the first input of which is connected to the output of the waiting multivibrator, and the output to the output bus, the output of the pulse shaper is connected to the input of the shift register.

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